Zero discharge

Zero Liquid Discharge (ZLD)Every litre back to work.

A ZLD plant recovers the water in your effluent and turns what is left into dry solids. Nothing liquid leaves the gate, and recovered water goes back into production.

Request a proposalHow it works
  1. 01Pre-treatment
  2. 02Clariflocculation
  3. 03Biological treatment
  4. 04Filtration
  5. 05UF and RO
  6. 06Evaporation (MEE)
  7. 07Drying (ATFD)

What it is

In plain words.

Zero liquid discharge is a treatment train built so that no wastewater leaves the site. Effluent first passes through conventional treatment, then membranes recover most of the water as clean permeate. The concentrated reject that remains is boiled down in evaporators and dried into solids. The result is reusable water on one side and a dry residue on the other, with no liquid stream to a drain or river.

Industries look at ZLD for many reasons: tighter disposal rules, consent conditions in sensitive river basins, rising water costs, or simply a shortage of fresh water. We design the full chain to suit your effluent, from oil traps and clariflocculators to UF, RO, MEE and ATFD, and we can operate and maintain it under an AMC.

How it works

Stage by stage.

  1. Pre-treatment

    Oil and grease trap, equalisation and neutralisation prepare the raw effluent.

  2. Clariflocculation

    A flash mixer and primary clariflocculator remove suspended solids and part of the pollutant load.

  3. Biological treatment

    Aeration breaks down organics, followed by a secondary clariflocculator to settle the biomass.

  4. Filtration

    Pressure sand and activated carbon filters polish the water ahead of the membranes.

  5. UF and RO

    Ultrafiltration protects the RO, which recovers clean water and leaves a concentrated reject.

  6. Evaporation (MEE)

    A multiple-effect evaporator boils off water from the reject, reusing steam across effects.

  7. Drying (ATFD)

    An agitated thin film dryer turns the concentrate into dry solids for disposal.

Options

Built to suit the site.

  • Membrane-led ZLD

    UF and RO recover most of the water, keeping the volume sent to evaporation as small as possible.

  • Thermal ZLD

    Evaporators and dryers handle high-salt streams that membranes cannot treat economically.

  • Hybrid ZLD

    Membranes and thermal stages combined, sized to balance capital cost, energy and recovery.

Where it's used

Industries and sites.

  • Pharma (API)
  • Textiles & dyeing
  • Distilleries
  • Paper & pulp
  • Specialty chemicals
  • Pesticides
  • Petrochemicals
  • Biotech

See how we work with each industry →

What we deliver

One team, from survey to service.

  • 01

    Design

    Survey, water or effluent analysis, process design and sizing for your site.

  • 02

    Build

    Supply, fabrication, civil and mechanical works, installation and commissioning.

  • 03

    Automate

    PLC, SCADA and remote monitoring, so the plant can be seen and controlled from anywhere.

  • 04

    Maintain

    Operation, preventive maintenance and AMC under Zeal-Care, with written reports.

Questions

Asked before every project.

Is ZLD compulsory for our unit?

It depends on your industry, location and consent order. Regulators have asked several sectors, particularly in the Ganga basin, to adopt ZLD, so check your consent conditions and we will help you read them.

What drives the running cost of a ZLD plant?

Mostly the energy and steam used by the evaporator and dryer. That is why we push as much recovery as possible through the membranes first, so less water has to be boiled off.

What happens to the dry solids?

The salts and sludge are collected and sent for disposal through an authorised facility, as your consent requires. Some streams allow salts to be recovered and reused.

Wastewater

Often built together.

Tell us about your site.

Share your flow, location and timeline. An engineer will review your requirement and call you back within one working day.

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